Comet Elenin on anyone's radar yet?

[IbiZen]

Dave, that's the easy part, we all agree with you but I think at this point we are way beyond that. The question is what do you think might happen on September 26/27 when it crosses between the Earth and the Sun and Earth probably transits the ion tail. We are not asking for predictions, just educated speculation.
Marc

[David Talbott]

As for the crossing of the ion tail, all we can say is that atmospheric effects on Earth would not be surprising and would offer further substantiation of the electric contribution to comet behavior. No one can say whether more energetic events (thunderbolts , etc.) will occur since there's too little information to go on. If, under electrical stresses, the comet begins to break up, that would obviously be a more dangerous situation. The Chicago Fire revisited.

Incidentally Marc, I don't quite see the "agreement" in this thread that you are referring to, and I don't think we should underplay the essential role of inescapable prediction in the upcoming events.

Dave

[IbiZen]

Thank you for your reply Dave
I believe that most of us agree with the "inescapable implications" of the visual potential of the comet based on the EU model, as stated so eloquently by you.
As far as implications of a break up, that would depend on the type of breakup we are talking about, because it would take a significant explosive breakup to alter the momentum of a fragment large enough to come close to Earth.
While the possibility of a breakup is significant, it involves so many variables that it make any discussion of its effects as fragmented as the comet would be.
With regard to the ion tail transit, could you be more specific as to what kind of phenomena might be observed that would substantiate the electric model, please.
Also, could you address the possible implications of the solar wind being slowed significantly by the ion tail as observed by Ulysses.
Sorry, I don't understand what you mean by inescapable prediction, especially in a case like this where there are so many variables and unknowns.
Dave, I am extremely excited about the possibility of a manifestation of symbols in the sky not seen since ancient times. As a historian, that interests me even more than the scientific angle, but, obviously they go hand in hand.
Think about this, on the morning of Sept. 27 Elenin will rise 10 minutes before the Sun, with the coma and tail lit up by the Sun behind it just 2 degrees off...and that is without taking into account any electric phenomena... inspirational !!!

Marc

[David Talbott]

Though I tend to avoid registering guesses on matter of uncertainty, an explosive break-up of a comet would mean a far greater release of charge, as in an exploding capacitor. What that would mean for a body passing through the ion tail would depend on many things, but I don't think one could rule out more intense electrical effects in Earth's atmosphere.

[IbiZen]

Now I understand what you mean. When you mentioned Chicago Fire I thought you meant by a charged fragment passing close. What you are saying is also complicated because there is the connection to the Sun, so which way does the charge flow? Is it split, or does it all go one way or the other?
I vote that for now we keep the comet in 1 piece...seems more interesting, less complicated...and possibly less dangerous....just call me a boring anti catastrophist.

[IbiZen]

A question to the forum...is it just me, or does it seem that flares that correspond to comets passing the sun don't look like they are directed at the comets themselves?

[markspann]

What I would really love to know is, is this comet likely to trigger one or more enormous CME's from the sun like we have seen from so many sun-grazing comets (thinking of NEAT 6 in 2003 and its three huge CME triggering events, two just prior to perehelion and one just afterwards as seen here http://www.youtube.com/watch?v=cX_FE6hOaqk


Even though Elenin it is not a sungrazer per se, it nonetheless will still be at an extreme potential difference with the sun's electric field even as it nears perihelion, so if it stays intact and does not break up prior to September 10th or so, are we likely to see massive CME's that might graze Earth just before or after that date, even before the Earth transits the plasma tail in October??

Just thinking outloud, not asking anyone to make predictions, just curious what ya'll are thinking with respect to comet triggered CME's.

So Dave, do you wanna take a stab at this?

[IbiZen]

Mark,
the first question is are there enough observation of this phenomena to establish a correlation pattern? A few comets seem to be associated with CME's, but most are not. Is there a common thread among the ones that seem to? Are the CME's directed at the comets? The only case I can find is Encke, where the CME ripped the tail off...which is a very interesting case in itself.
Marc

[IbiZen]

Message from Leonid Elenin

Leonid Elenin
My blog is reopen! Welcome! http://spaceobs.org/en/

[Dotini]

Leonid Elenin has calculated the following:

"March 31, Comet Elenin passes 1,366,500 km (0.009 AU) from asteroid 2001 SC155. On the same day, nearby, at a distance of 1,255,000 km (0.084 AU) and 1,365,500 km (0.009 AU) it encounters another two asteroids – 2005 NF30 and 2007 FR10 respectively. The closest approach will be April 2 – the comet and asteroid 2001 WA49 will pass by each other at only 335,500 km, which works out to 0.87 LD (the average distance from the Earth to the moon)!" http://spaceobs.org/en/tag/comet-elenin/

Therefore, this might be a good moment to look for an outburst or efflorescence of the coma.

Respectfully submitted,
Dotini

[The Great Dog]

TPOD: Sungrazers

...are we likely to see massive CME's that might graze Earth just before or after that date...

If the comet comes within a trigger distance, according to the TPOD. That distance probably varies because the solar dynamics vary from moment to moment and each comet is unique.

TGD

[goodsamaritan]

Real video of comet Elenin: 52 images

http://www.youtube.com/watch?v=lGDjPaelzjU

Picture of comet elenin: coma size estimate: Thirty Three Thousand Seven Hundred Kilometers

http://gustavomuler.fotografiaastronomi ... 03-J47.jpg

Follow this astronomer on youtube

http://www.youtube.com/user/gusmul1

[Dotini]

Leonid Elenin has made new observations of his comet, and determined the coma has grown to 80,000 km, this together with a close encounter with a substantial body in the asteroid belt. http://spaceobs.org/en/tag/comet-elenin/

Respectfully,
Dotini

[mharratsc]

Very interesting kick in the coma size seemingly due to the proximity to that asteroid...

So- would we expect to see a similar kick up in the coma by proximity to Earth? Or has the asteroid done most of the work of charge equalization for the inner system bodies, and we shouldn't expect to see much more coma growth in its passage near our planet?

I guess it would be dependent on the amount of charge differential between asteroidal bodies and the Earth (of which I know nothing whatsoever).

Any wise members want to take a stab at this question for me?

[jjohnson]

Am not a particularly wise member but would like to ask a couple of relevant questions.

What mechanism is responsible for increasing the size of a comet's coma? Does the electrostatic charge on the comet increase to expand it, and what would be the source of that increase?

How would a "close encounter" (10 km? 10,000 km?) with an asteroid that is simply orbiting in the asteroid belt increase the coma? Is charge transferred between the two bodies due to a voltage differential? Whence the charge? Could it be the solar wind? Why would that omnipresent source charge up an asteroid to a higher voltage that that of the comet? Can the solar wind charge something up to a voltage higher than that of the solar wind?

Is it something other than electrostatic charge? is it simply the change in solar EM field value which controls the coma, or its voltage relative to the comet? Could that have changed coincidentally with the close encounter?

Does the coma expand when the solar field strength decreases (less active wind), thus increasing the "pressure" on the coma by the comet's charge level?

The E-COMET pdf (find it in the Resources section of this site, under e-books in the right hand sidebar, available from Mikimar Publishing) explains that as a comet, negatively charged relative to the Sun, accelerates inward toward the sun, it enters a region of higher positive charge (voltage), increasing the strength of its electric field, causing its plasma sheath to expand along with the start of arcing on and machining of the surface, especially on sharp edges of craters, rocks, etc. This arcing sputters off fine dusty particles as well as breaks molecular bonds of local materials, accelerating various ionized species such as OH (hydroxyl ions) and others into the coma.

An earlier comet, Comet Holmes was moving away from the Sun in 2007 when it inexplicably brightened and increased its com's size so much that it became visible to the naked eye. E-COMET notes that "...outbursts from comets at great distances from the Sun seem to correlate with sudden changes in the solar "wind" plasma environment due to a solar storm."

Can we correlate the arrival of a solar storm or solar wind outburst in the vicinity of Comet Elenin with its "close encounter" with a "substantial body" in the asteroid belt? Would Elenin have brightened whether or not it happened to be near a body? Idea: There are a lot of bodies in the asteroid belt, and the chances might be good that a comet at that distance might happen to be relatively near one of them when it was caught in a surge in the strength of the solar wind.

Jim